1. Field of the Invention
This invention relates to a chucking and focusing device for a telescope eyepiece and its production process, particularly to one possible to clamp and focus an eyepiece without significant eccentricity, and a method for producing it.
2. Description of the Prior Art
A conventional Newtonian reflective telescope shown in FIGS. 1 and 2, includes a tubing body 10, an eyepiece barrel 20 fixed vertically on one side of the barrel body 10 and having one end fitting around an eyepiece 21. The eyepiece 21 and the eyepiece barrel 20 are tightly combined together with a screw 22. The eyepiece barrel 20 comprises an outer tube 23 and an inner tube 24, and the outer tube 23 is connected tightly with tubing body 10. Further, two adjusting wheels 240 are provided to be connected with the outer tube 24, and a worm 241 connects the two adjusting wheels 240. The inner tube 23 has a rack 230 fixed lengthwise on its outer surface, and the rack 230 engages the worm 241 in case of the inner tube 23 extending in the outer tube 24, so that the worm 241 rotates when the adjusting wheel 240 is rotated for adjustment. The rack 230 and the inner tube 23 are extended or retracted for focusing the eyepiece 21, according to the rotation of the adjusting wheels.
However, the conventional telescope has following disadvantages in usage.                1. The eyepiece 21 has one end extending and fixed in the inner tube 23 of the eyepiece barrel 20, by the screw 22 entering the inner tube 23 and clamping the eyepiece 21. This way of fastening obviously pushes the optical axis of the eyepiece 21 away from the axis of the eyepiece barrel causing eccentricity between two axes, and thus causing difficulty of focusing for a good image quality.        
2. When the inner tube 23 and the outer tube 24 are adjusted in their length, it has to depend on matching movement of the two adjust wheels 240, the worm 241 and the rack 230, complicated in its structure, and subsequent high cost, and rather slow in its adjusting speed.